The Indiana Residential Building Code is based on the 2003 IRC with state amendments (eff. 9/11/05). This code applies to 1 and 2 family dwellings and townhouses. During the adoption process, certain seismic provisions were weakened, primarily affecting nine southwestern counties. Local jurisdictions may amend to make the code more stringent with state approval only.
The Building Code Enforcement Branch under the Fire and Building Safety Commission encourages the development of building code law enforcement programs within state agencies and political subdivisions and exercises any program of supervision that is approved by the Fire Prevention and Building Safety Commission. The branch enforces building laws and related variances as well as other orders that apply to Class I structures (buildings other than one- and two-family dwellings), industrialized buildings and mobile structures. The local building official is responsible for the enforcement of the requirements for all one- and two-family dwellings (Class 2).
Currently, the commercial code references ASHRAE 90.1-2007 and the residential code references 2009 IECC and 2009 IRC.